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Digestive Condition

Diarrhoea
Acute, Chronic and What's Actually Driving It

Acute diarrhoea is one of the most common illnesses in India and usually resolves on its own within a few days. But chronic diarrhoea, defined as loose or watery stools lasting more than four weeks, is a different beast entirely. It has a long list of possible causes, many of which are missed in standard workups, and it carries real risks including nutrient malabsorption and significant impact on quality of life. If you've been dealing with loose stools for months and haven't had a thorough investigation, this is worth reading.

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Dr. Chhavi Bansal Diarrhoea Treatment
Dr. Chhavi Bansal
Homeopathic Physician · HomeoSure
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Quick Answer

Diarrhoea is categorised as secretory (the gut secretes excess fluid), osmotic (unabsorbed substances draw water into the gut), inflammatory (gut lining damage causes fluid loss), or motility-related (the gut moves contents too fast for water absorption). Acute diarrhoea is almost always infectious. Chronic diarrhoea can be caused by IBS-D, IBD (Crohn's disease or ulcerative colitis), coeliac disease, microscopic colitis, bile acid malabsorption, lactose or fructose intolerance, parasitic infections like giardia, or post-infectious changes. Each cause has a different investigation and a different treatment approach.

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Chronic diarrhoea lasting more than four weeks needs systematic investigation, not just antidiarrhoeal medication. Book a consultation with Dr. Chhavi Bansal today.

How Diarrhoea Works

Normal stool is around 75 percent water. Diarrhoea occurs when water content rises above that threshold, either because the gut is secreting excess water, because something in the gut is drawing water in osmotically, because the gut is moving contents too fast to absorb water normally, or because gut lining damage is preventing proper absorption.

In secretory diarrhoea, the gut epithelium actively secretes chloride and sodium, drawing water with it. This happens with certain bacterial toxins (cholera is the extreme example), with bile acid malabsorption, and with some hormonal tumours. In osmotic diarrhoea, unabsorbed substances in the gut draw water in by osmosis. Lactose reaching the colon undigested is a classic example. In motility-driven diarrhoea, the gut propels contents too fast, which is common in IBS-D and hyperthyroidism.

Warning Signs That Require Prompt Investigation

🩸 Blood or mucus in stool
🌡️ Fever accompanying diarrhoea
⚖️ Unexplained weight loss
😴 Severe fatigue or weakness
😣 Nocturnal diarrhoea waking you from sleep
🔄 Diarrhoea lasting more than four weeks
🌍 Travel-associated diarrhoea that doesn't resolve
💊 Diarrhoea starting after a course of antibiotics

The Missed Causes Checklist

Standard IBS-D management misses several conditions that cause chronic diarrhoea. Microscopic colitis (collagenous or lymphocytic colitis) is invisible on routine colonoscopy but shows up on biopsy. Bile acid malabsorption is never diagnosed without specific testing. Giardia in chronic low-grade infection is missed without antigen testing. Coeliac disease presents with diarrhoea and weight loss and is still routinely missed without serology. Each of these has a specific treatment that works, but you can't treat what you haven't identified.

Commonly Missed Causes of Chronic Diarrhoea
  • Microscopic colitis (requires biopsy, not just colonoscopy)
  • Bile acid malabsorption (requires SeHCAT or specific blood test)
  • Chronic giardia infection (requires antigen test, not just stool exam)
  • Coeliac disease (requires anti-tTG IgA serology)
  • Lactose intolerance driving loose stools
  • Hyperthyroidism (thyroid function not always checked in diarrhoea workup)
  • SIBO with diarrhoea-predominant pattern
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Patient Story

A Real Recovery Story

"

Anjali had loose stools every morning for 18 months. She'd been treated for IBS-D with antispasmodics without improvement. What hadn't been tested was bile acid malabsorption, which is a commonly missed cause of morning diarrhoea particularly in people who've had their gallbladder removed. Anjali hadn't had her gallbladder out, but bile acid malabsorption also occurs idiopathically. A SeHCAT test and subsequent bile acid sequestrant treatment made a dramatic difference within three weeks. She wishes someone had investigated it earlier."

A
Anjali R.
Patient · Mumbai · treated at HomeoSure
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Common Questions

Frequently Asked Questions: Diarrhoea

Acute diarrhoea lasts less than two weeks and is almost always infectious (bacterial, viral, or parasitic gastroenteritis). It typically resolves with supportive care (hydration, rest) and occasionally antibiotics if bacterial. Chronic diarrhoea is defined as lasting more than four weeks. This time threshold matters because it virtually rules out acute infection as the primary cause and opens a much longer list of diagnoses: IBS-D, IBD, coeliac disease, microscopic colitis, bile acid malabsorption, parasitic infections (giardia in particular can persist for months), food intolerances, and more. Chronic diarrhoea requires systematic investigation, not just supportive management.
Bile acids are produced in the liver and secreted into the small intestine to help absorb fats. Normally, about 95 percent of bile acids are reabsorbed in the terminal ileum (the end of the small intestine) and recycled. When reabsorption fails, excess bile acids reach the colon, where they stimulate water secretion and speed up motility, causing watery diarrhoea. This is more common after ileal surgery or Crohn's disease involving the ileum, but also occurs idiopathically (type 2 bile acid malabsorption) with no obvious cause. It's highly responsive to treatment with bile acid sequestrants, but is frequently missed because it requires a specific test (SeHCAT scan or serum 7a-hydroxy-4-cholesten-3-one) that isn't routinely ordered.
A thorough workup for chronic diarrhoea includes: full blood count and inflammatory markers (ESR, CRP), coeliac serology (anti-tTG IgA), thyroid function (hyperthyroidism causes diarrhoea), stool examination for infections and parasites including giardia, faecal calprotectin (elevated in IBD, normal in IBS), colonoscopy with biopsies (to identify IBD, microscopic colitis, and other structural causes), and in selected cases, hydrogen breath testing for SIBO or bile acid testing. The sequence and what gets prioritised depends on the symptom pattern, age, red flags, and travel history.
Yes. The gut-brain axis means that anxiety and stress genuinely affect gut motility through the autonomic nervous system. People with anxiety-driven diarrhoea often notice it correlates closely with stressful periods, mornings before important events, or situations where they feel anxious. IBS-D with prominent anxiety is a recognised pattern. But this doesn't mean anxiety is the only cause or that diarrhoea in an anxious person should be attributed entirely to anxiety without investigation. The two can coexist, and gut inflammation or dysbiosis can also drive anxiety via the same gut-brain axis.
Seek prompt medical attention for: diarrhoea with blood or mucus in stool, diarrhoea with fever above 38.5 degrees Celsius, signs of dehydration (dry mouth, dark urine, dizziness, reduced urination), diarrhoea in elderly people, infants, or immunocompromised individuals (dehydration risk is higher), diarrhoea after travel to high-risk areas (parasites and resistant infections are more likely), diarrhoea associated with significant weight loss, or diarrhoea that's been present for more than two weeks without improvement. These are red flags that need investigation beyond basic supportive care.
No, and this is one reason it's frequently missed. Giardia lamblia is a parasitic infection transmitted through contaminated water or food. Acute giardia causes watery diarrhoea, nausea, bloating, and fatigue. But some people develop a chronic low-grade infection where symptoms are less dramatic: loose stools that come and go, persistent bloating, malabsorption, fatigue, and IBS-like symptoms. This can persist for months and be attributed to IBS without the parasitic cause being identified. Stool examination for ova and cysts, or a giardia antigen test, is the diagnostic step. A history of travel to areas with contaminated water or a prior acute gastroenteritis episode should prompt specific testing.

Chronic diarrhoea without a clear answer?

Diarrhoea lasting weeks or months deserves thorough investigation, not just symptom management. Book a consultation to identify what's actually driving it.

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